The properties mainly required for wound coverings are 1. adhesiveness, 2. flexibility, 3. durability, 4. ease in handling, 5. shelf stability, 6. blocking property against bacteria, 7. affinity to a vital body, 8. hemostatic property, 9. water-vaporization controlling ability, 10. exudate-draining property, etc.
In treating a wound such as a burn, although the treating method depends on the depth and area of the wound, it is common to use a wound covering comprising a polyurethane resin or a silicone resin, or an artificial skin (a wound covering) made of e.g. chitosan, collagen or a chitosan-collagen complex (Japanese Unexamined Patent Publication No. 253065/1986), or to apply a cream containing an antibacterial agent (Geben cream, trade name) to the burn, cover it with a gauze and fix the gauze by a bandage.
In the method in which a cream containing an antibacterial agent (Geben cream, trade name) is applied to the burn, and a gauze is put thereon and fixed by a bandage, it is necessary to change the gauze in a frequency of from several times per day to once in several days, and there are problems that cumbersome operations give a great deal of pain to a patient and require substantial care by the treating person.
Further, among wound coverings currently used, few have properties 1. to 10. described above, and they are still far from being satisfactory.
On the other hand, a cultured skin which uses cells derived from the skin and is aimed at a permanent take, is used in treatment of a burn patient, in addition to a wound covering which covers the wound surface temporarily. However, it is difficult for a cultured skin to maintain a constant take rate because of its weakness in physical strength and resistance against infection. In order to improve the take rate of a cultured skin, it is important to form a better transplantation bed. It is also desired to study such a covering which is capable of providing a suitable environment for the take of such a cultured skin.